From: tip-bot for Denys Vlasenko <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: bp@suse.de, rostedt@goodmis.org, dvlasenk@redhat.com,
keescook@chromium.org, fweisbec@gmail.com, ast@plumgrid.com,
wad@chromium.org, luto@amacapital.net, mingo@kernel.org,
bp@alien8.de, linux-kernel@vger.kernel.org, hpa@zytor.com,
oleg@redhat.com, torvalds@linux-foundation.org,
tglx@linutronix.de
Subject: [tip:x86/asm] x86/asm/entry/64: Fold the 'test_in_nmi' macro into its only user
Date: Thu, 2 Apr 2015 05:33:02 -0700 [thread overview]
Message-ID: <tip-0784b36448a2a85b95b6eb21a69b9045c896c065@git.kernel.org> (raw)
In-Reply-To: <1427899858-7165-1-git-send-email-dvlasenk@redhat.com>
Commit-ID: 0784b36448a2a85b95b6eb21a69b9045c896c065
Gitweb: http://git.kernel.org/tip/0784b36448a2a85b95b6eb21a69b9045c896c065
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Wed, 1 Apr 2015 16:50:57 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 2 Apr 2015 12:00:10 +0200
x86/asm/entry/64: Fold the 'test_in_nmi' macro into its only user
No code changes.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427899858-7165-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/entry_64.S | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 03c52e2..386375d 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1355,19 +1355,7 @@ ENTRY(error_exit)
CFI_ENDPROC
END(error_exit)
-/*
- * Test if a given stack is an NMI stack or not.
- */
- .macro test_in_nmi reg stack nmi_ret normal_ret
- cmpq %\reg, \stack
- ja \normal_ret
- subq $EXCEPTION_STKSZ, %\reg
- cmpq %\reg, \stack
- jb \normal_ret
- jmp \nmi_ret
- .endm
-
- /* runs on exception stack */
+/* Runs on exception stack */
ENTRY(nmi)
INTR_FRAME
PARAVIRT_ADJUST_EXCEPTION_FRAME
@@ -1428,8 +1416,18 @@ ENTRY(nmi)
* We check the variable because the first NMI could be in a
* breakpoint routine using a breakpoint stack.
*/
- lea 6*8(%rsp), %rdx
- test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi
+ lea 6*8(%rsp), %rdx
+ /* Compare the NMI stack (rdx) with the stack we came from (4*8(%rsp)) */
+ cmpq %rdx, 4*8(%rsp)
+ /* If the stack pointer is above the NMI stack, this is a normal NMI */
+ ja first_nmi
+ subq $EXCEPTION_STKSZ, %rdx
+ cmpq %rdx, 4*8(%rsp)
+ /* If it is below the NMI stack, it is a normal NMI */
+ jb first_nmi
+ /* Ah, it is within the NMI stack, treat it as nested */
+ jmp nested_nmi
+
CFI_REMEMBER_STATE
nested_nmi:
prev parent reply other threads:[~2015-04-02 12:33 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-01 14:50 [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Denys Vlasenko
2015-04-01 14:50 ` [PATCH] x86/asm/head/64: Use __BOOT_TSS instead of literal 0x20 Denys Vlasenko
2015-04-01 16:46 ` Borislav Petkov
2015-04-01 17:01 ` Steven Rostedt
2015-04-02 12:33 ` [tip:x86/asm] x86/asm/boot/64: Use __BOOT_TSS instead of literal $0x20 tip-bot for Denys Vlasenko
2015-04-01 15:45 ` [PATCH] x86/asm/entry/64: fold test_in_nmi macro into its only user Steven Rostedt
2015-04-02 12:33 ` tip-bot for Denys Vlasenko [this message]
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